Soluble cutting oil and method of preparing the same



Patented Aug. 13, 1940 UNITED STATES SOLUBLE CUTTING OIL AND METHOD OFPREPARING THE SAME Paul T. Anderson, Park Ridge, and Harry Moir,Chicago, Ill., assignors to The Pure Oil Company, Chicago, Ill., acorporation of Ohio No Drawing. Application July 17,1936, Serial No.91,098

12 Claims.

This invention relates to cutting oils and lubricants and to the methodof making the same. The invention is more particularly concerned withsoluble cutting oils and lubricants.

It is common practice to employ oils in grinding, polishing and cuttingmetallic bodies of various kinds. The oil serves a dual function as acoolant and as a lubricant. It is important that the oil used have ahigh film strength under the high pressures to which it is subjectedduring the cutting, grinding or polishing operation. When the filmstrength of the oil is insufficient, frequent dressing of the abrasivegrinding, cutting or polishing wheel is necessary, with the result thatthe operation is time consuming.

This invention resides in a novel cutting oil which not only enablescutting operations to be performed in considerably less time thanheretofore but also enables grinding and polishing to be done in oneoperation in less time than is required with present known cutting oilsto perform the grinding operation alone. Furthermore, with present typesof cutting oils, separate grinding and polishing operations arenecessary, whereas grinding and polishing may be accomplished in oneoperation when oil prepared in accordance with this invention is used.0n certain types of metal, as for example, aluminum, it is possible toobtain a higher polish than heretofore.

The composition to which this invention relates may be prepared bysulfurizing and then phosphorizing a vegetable, animal or marine fat oroil and preparing a homogeneous mixture or solution of the sulfurizedand phosphorized body with a major portion of a mineral lubricating oiland a suflicient amount of emulsifying agent to allow the material toemulsify when mixed with water. As an emulsifying agent, varioussulfonated fatty oils, sulfo-aromatic compounds of fatty oils, such asTwitchell reagent, and naphthenic or sulfo-naphthenic acid soaps, may beused. This composition may be mixed with water in various proportionsdepending upon the consistency of the material desired for the cutting,grinding or polishing operation.

When using naphthenic acid or sulfa-naphthenic acid soaps and otheremulsifying agents, it may be necessary to add a small percent of anhomogenizing agent to the composition to pre-- vent separation intolayers. For this purpose, poly-hydroxy alcohols such as diethyleneglycol, glycerine and the higher mono-hydroxy alcohols such as butyl andamyl alcohols, may be used.

The composition prepared in accordance with the invention is highlysensitive to small amounts of reagents normally found in water. Incertain instances the composition may readily emulsify with the water,whereas in other instances a satisfactory emulsification cannot beobtained. It may therefore be necessary in some cases to treat the waterto remove therefrom the emulsifying inhibitors. For best results thewater should have a pH value of approximately 7 and should not varytherefrom more than 0.5. Generally, the addition of either causticalkali or of fatty acid, such as oleic acid, in amounts of 0.1% orproduce emulsification has been determined, this amount can be used inpreparing the emulsion for commercial use. a

The sulfurized and phosphorized material used in the composition may beprepared in the following manner:

A lubricating oil, preferably obtained from Gulf Coast crude, may bemixed with sulfur chloride in the proportions of 5 parts of the formerto 0.5 of a part by weight of the latter.

This mixture may then be incorporated with ap- I proximately 87 parts byweight of prime lard oil and the mixture slowly heated to approximately270 F. At this temperature 7 .4 parts by weight of finely ground flowersof sulfur may be added over a period of about 10 minutes. After theaddition of sulfur the temperature of the mixture may be raised toapproximately 330 F. and held at this temperature until the mixtureshows no corrosion when a copper strip is dipped into it. The period ofheating may require approximately '7 hours. During the heating themixture should be continuously agitated. The resulting composition isthen cooled rapidly to approximately F. and then may be permitted tocool slowly to room temperature. The sulfurized material thus preparedmay be used in that state as a constituent of the cutting oil base, orthis material may be phosphorized by mixing with 99.6 parts of thesulfurized lard oil, 0.4 of

a part of finely divided phosphorus sesquisulfide H and the mixtureheated to a temperature of approximately 220-230 F. for a period of 5hours with constant agitation. The resulting material may then be cooledto form the final sulfurized and phosphorized base. outlined is thepreferable method for preparing the sulfurized and phosphorized bases,it will be understood that the preparation is not limited to thespecific procedure outlined, nor to the specific quantities ofingredients.

Although the method The sulfurized and phosphorized base made in theaforesaid manner may be blended with a Gulf Coast lubricating oil havingthe following characteristics:

Table I A. P. I. gravity 21.2 Flash F 350/360 Fire F 385/395 Viscosity100 F 200/210 Viscosity 210 F 42/45 Pour "F 20/--25 and with anemulsifying agent. In some cases diethylene glycol or other homogenizingagent may be added. Twitchell reagent may be used as the emulsifyingagent. Sodium sulfonaphthenate may also be used for this purpose, eitheralone or mixed with Twitchell reagent.

The sodium naphthenates or sodium sulfonaphthenates used in thecomposition may be obtained from the treatment of Gulf Coast oils; Forexample, where it is desired to obtain sodium naphthenate, an oilfraction containing naphthenic acids may be mixed with a 5-6 Baumcaustic soda solution and the resulting soap solution skimmed from theoil. To the soap solution sufiicient sulfuric acid may be added toproduce a neutral solution when tested with methyl orange. The solutionis preferably agitated with air during the adding of acid. Thenaphthenic acids are liberated and separate as a top layer.

In certain instances it may be desirable to distill the resultingnaphthenic acids in order to separate a fraction of the desiredproperties. In the distillation the temperature should not exceed 600.F. and distillation should be carried out in the presence of steam.

The sulfo-naphthenic acids may be obtained from Gulf Coast oils whichhave been treated with sulfuric acid. The acid treated oil may beneutralized with caustic soda solution and the water layer whichcontains in solution or suspension the sulfo-naphthenic acid soaps, maybe withdrawn and acidified. The sulfo-naphthenic acids will separate asa top layer and. can be slnmmed.

A composition was made by blending together the following materials inthe proportions stated:

Table II Percent Emulsifier (consisting of 75% naphthenic acid soap25%Twitchell reagent) Sulfurized and phosphorized base 10 Lubricating 011(Table I) 74 Diethylene glycol 1 Table III PercentSulfurized-phosphorized base l0 Sulfa-naphthenic acid soap 10Lubricating oil (Table I) '78 Diethylene glycol 2 This composition waslikewise emulsified with parts of water to 1 part of the composition andproduced an emulsion which resulted in very little separation.

A third emulsion was produced by mixing a composition containing thefollowing:

Table IV Percent Twitchell reagent Sulfurized-phosphorized base 10Lubricating oil (Table I) 65 with 10 parts of water to 1 part of thecomposition. This emulsion like the preceding two, was very stable.

Although the specific examples given show blends of 1 part ofcomposition to 10 to 20 parts of water, the composition may be blendedwith water in any proportion from 1 part of composition to 1 part ofwater up to approximately 50 parts of water to 1 part of thecomposition. 1 part of composition to parts of water has been found togive excellent results for cutting and grinding purposes.

The soluble base prepared in accordance with the invention is in aliquid form, and in those cases where naphthenates or sulfo-naphthenatesare used as emulsifying agents, it is desirable to add a small amount ofhomogenizing agent, such as diethylene glycol, to-keep the material fromseparating into layers, since the material after separation emulsifieswith the water only with great difiiculty.

In the specific examples given, a sulfurized and phosphorized base wasused, but excellent cutting oils may be made from sulfurized materialwhich has not been phosphorized.

It is to be understood that although in the examples, specificquantities of various constituents have been given, and specificconstituents have been named, the examples are given only for purpose ofillustration and the invention is not intended to be limited to eitherthe specific amounts of materials or the specific materials, but broadlyinclude other materials falling within the same general class orexhibiting the same functions as the materials specifically named.

Wherever used in the specification or claims the term sulfurized shallmean the chemical combination of sulfur and/or sulfur chloride withfatty material and the term phosphorized" shall mean the chemicalcombination of phosphorus either elemental or in combination with otherelements, with fatty material.

What is claimed is: I

1. A soluble cutting oil base comprising a major portion of minerallubricating oil and minor portions of fatty material which has beensulfurized and then phosphorized, an emulsifying agent, and anhomogenizing agent.

2. A cutting Oil base in accordance with claim 1 in which thehomogenizing agent is a material selectedfrom the group consisting ofbutyl alcohol, amyl alcohol, glycerine and diethylene glycol.

3. A cutting oil base in accordance with claim 1 in which theemulsifying agent comprises saponified sulfonated mineral oil acids.

4. A cutting oil base in accordance with claim 1 in which theemulsifying agent comprises saponified sulfonated mineral oil acids, andthe homogenizing agent comprises compounds selected from the classconsisting of mono-hydroxy alcohols of four or more carbon atoms andpolyhydroxy alcohols.

5. Method of preparing a soluble cutting oil base which comprisessulfurizing fatty oil at elevated temperatures, phosphorizing thesulfurized oil, and compounding the sulfurized and phosphorized oil withmineral lubricating oil and an emulsifying agent.

6. Method in accordanc with claim 5 in which the sulfurized andphosphorized fatty oil is compounded with a major portion of minerallubricating oil, a minor portion of saponified sulfonated mineral oilacid and sulfo-aromatic fatty acid and a still smaller portion ofdiethylene glycol.

'7. The method of preparing an emulsion of a cutting oil which comprisesagitating with water until emulsiflcation takes place, an emulsifyingagent, an homogenizing agent and a composition prepared by mixing 5parts by weight of a lubricating 011, 0.5 of a part of sulfur chlorideand 87 parts by weight of lard oil, slowly heating the mixture to 270F.. then slowly adding 7.4 parts by weight of flowers of sulfur, raisingthe temperature to approximately 330 F. and holding the mixture at thistemperature until it shows no corrosion to a copper strip, cooling toabout 225 F. and adding 0.4 of a part of phosphorus sulfide to 99.6parts of the sulfurized oil, holding the mixture at this temperature forapproximately 5 hours and then cooling.

8. A soluble cutting oil comprising a major portion of a minerallubricating oil and minor portions of an emulsifying agent and amaterial prepared by chemically reacting sulfur chloride and sulfur witha fatty oil at elevated temperatures and then reacting the sulfurizedoil with a sulfide of phosphorus at elevated temperatures, and coolingthe reaction product.

9. A soluble cutting oil in accordance with claim 8 in which the fattyoil is lard oil.

10. Method of preparing a soluble cutting oil base which comprisescompounding with mineral lubricating oil and an emulsifying agent, amaterial prepared by mixing 5 parts by weight of a lubricating oil, 0.5of a part of sulfur chloride and 87 parts by weight of fatty oil, slowlyheating the mixture to 270 F., then slowly adding 7.4 parts by weight offlowers of sulfur, raising the temperature to about 330 F. and holdingthe mixture at this temperature until it shows no corrosion to a copperstrip, cooling to about 225 F. and adding 0.4 of a part of a sulfide ofphosphorus, holding the mixture at this temperature for approximately 5hours, and then cooling.

11. Method in accordance with claim 10 in which the fatty oil is lardoil.

12. A soluble cutting oil comprising a major portion of a minerallubricating oil, minor portions of an emulsifying agent and a materialprepared by chemically reacting .5 part by weight of sulfur chlorideand7.4 parts by weight of sulfur with 87 parts by weight of lard oil atelevated temperatures and then reacting 99.6 parts of the sulfurizedlard oil with .4 part by weight of phosphorus sesquisulfide at elevatedtemperatures and cooling the reaction product.

PAUL T. ANDERSON.

HARRY L. MOIR.

